Commercial shrimp farms suffer extensive losses due to the effects of a number of common pathogens. Taura Syndrome Virus (TSV) is one of the most serious viral pathogens of farmed penaeid shrimp. It is widely distributed in many countries and has a large range of hosts. The most susceptible shrimp species to TSV are Pacific white shrimp (Liptopenaeus vannamei) and the white shrimp (Liptopenaeus schmitti). Other susceptible species include brown shrimp (Farfantepanaeus aztecus), pink shrimp (Farfantepanaeus duorarum), and white shrimp (Liptopenaeus setiferus). TSV is a single stranded RNA virus, the complete genome of which has been sequenced (GenBank AF277675).
TSV infects juvenile shrimp within two to four weeks of stocking into grow-out ponds or tanks and can cause high mortality. Detection of TSV in hatchery broodstock and in post-larvae allows infected shrimp to be eliminated before entry into a commercial production system. Consequently, a variety of methods have been developed for the detection of TSV in shrimp, including nucleic acid-based methods and immunological methods (You et al. Current Topics in Virology 4:63-73 (2004); and Lightner et al., Aquaculture 164(1):201-220 (1998)). Polymerase chain reaction (PCR) based methods are of particular interest because they are simple, rapid, and sensitive. Reverse transcriptase-polymerase chain reaction (RT-PCR) methods for the detection of TSV, which are based on amplifying different diagnostic regions of the genome, have been described (see for example, Tang et al., J. Virol. Methods 115(1):109-114 (2004); Mouillesseaux et al., J. Virol. Methods 11(2):121-127 (2003); Nunan et al., Dis. Aquat. Org. 34(2):87-91 (1998); Dhar et al., J. Virol. Methods 104(1):69-82 (2002); and Nunan et al., Aquaculture 229(1-4):1-10 (2004)).
All of the above methods are useful for the detection of TSV; however, they generally suffer from a lack of specificity, sensitivity, or are complex and time consuming. Additionally, because of the high gene mutation rate in the virus, tests directed to different regions of the genome would be useful. Therefore, there is a need for a highly sensitive assay for TSV that is rapid, accurate and easily used in the field. The stated problem is addressed herein by the discovery of primers based on new portions of the TSV genome. The primers identified herein can be used in primer directed amplification or nucleic acid hybridization assay methods for the detection of TSV without the problems associated with previous methodologies.